Installation manual
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ENGINE
ADJUSTMENTS
ADJUSTING
VALVE
CLEARANCES
1. Remove the cylinder head rocker cover.
2. Manually rotate the engine crankshaft and bring
#1
piston up on TDC
of
its compression stroke.
NOTE:
When this occurs, the intake
and
exhaust cam
lobes will face upwards.
3. Measure the valve clearance
of
#1
cylinder by using a
thickness gauge.
Standard Valve Clearances (Engine Cold):
Intake:
0.20 - 0.30mm (0.008 - 0.012 in)
Exhaust:
0.30 - 0.40mm (0.012 - 0.016 in)
VALVE
CLEARANCE
MEASUREMENT.
If
the valves clearances are not within standard
values, continue using the following procedure to
adjust the valves.
4. Rotate the valve cam lobe so that it points straight
upward.
5. Rotate the tappet so that one
of
the notches is facing
the exhaust manifold. This allows for better access to
the adjusting disc.
6. Using the tappet holder WESTERBEKE #41978,
press the tappet down to the position where the
adjusting disc becomes accessible.
23
7. Using a small screwdriver or magnet, remove the
adjusting disc.
8. Select an appropriate disc thickness depending on the
clearance measured. Install it and verify proper
clearance.
EXAMPLE
(Intake Valve): The thickness
of
the disc
removed plus the clearance measured minus the
standard clearance will give the thickness
of
the new
adjusting disc.
4.0 mm + (0.30 - 0.25 mm) = 4.05
mm
0.157 in + (0.012 - 0.010 in) = 0.159 in
NOTE:
The number marked on the disc indicates
its thickness. Example:
3825 means 3.825mm (0.1056
in). Adjusting discs are available in 25 different
thicknesses between
3.40 and 4.60mm (0.1339-
0.1811 in) range,
at
variations
of
0.050 mm (0.002
in).
9. Measure and adjust as needed the valves in cylinders
#3,
#4
and #2 following the instructions above.
CAM
(INTAKE)'\...
VALVE
CLEARANCE